Question: This lovely "Christmas colour-theme" Thai mystery bird is named for a unique trait. What trait is that? Can you identify this mystery bird's taxonomic family and species?

Response: This lovely creature is a vernal hanging parrot, Loriculus vernalis, a very small parrot that is found throughout Burma, southern and southeastern India and southeastern peninsular Thailand. This parrot is placed into the Psittacidae, or the family of true parrots.

The 13 species of hanging parrots and they all share a number of traits: they all are small, short-tailed, and primarily emerald green-plumaged birds that are found in southeast Asia. They unique amongst birds for their ability to sleep upside down, thus, their common name, hanging parrots.

They all feed on fruits, berries, nuts, nectar and blossoms and they will irrupt in search of food.

Here's a video of a vernal hanging parrot feeding on fruit at Orchard Mile near Kaeng Krachan National Park in Thailand (uploaded 20 December 2009):

Hanging parrot species are easiest to distinguish based on the colours and patterns on their heads. The vernal hanging parrot's range overlaps that of blue-crowned hanging parrots, L. galgulus, but they can be distinguished by the vernal hanging parrot's orange or reddish-orange bills and subtle blue bib (although females lack this). Additionally, adult vernal hanging parrots in breeding condition have white irises (blue-crowned hanging parrots have dark eyes).

The vernal hanging parrot prefers deciduous forest, secondary growth or mixed brush and thin jungle, but also pops up occasionally in evergreen forest, especially when flowering trees are nearby. They are a cavity-nesting species, preferring to enlarge already-existing tiny holes in stumps or rotten trees. They lay between two and four eggs per clutch and the chicks are born blind and helpless.